Or, anyone that can answer it.

I've heard of rolling hills most of my life, but I've never SEEN, a hill ROLL. Not even on television.
Any explanation?

Falls under the same topic as "rolling your r's."

None that I can think of. Roll is used quite a bit to describe unusual events or things. "Roll a drunk.", "Roll out the first drunk.", "Rock and Roll", "Let's roll.", "Roll on, Mississippi.", "Rollmops" (pickled herring).

Well Steve, if you can't solve the mystery , it may go down as one of those cold cases.

In the Great Plains, where wheat fields grow at their greatest height, the hills of wheat roll when the wind is most high.

Never seen a hill roll ..... But ... They say where I live in middle Tennessee that we have rolling hills. The hills go on and on.. Up one hill then down to a valley then up another hill... So I always assumed that's why they said that. But you know what folks say about assuming..

how about roll out the barrel,roll a smoke,or roll a tire,or roll over